Bumping gaia.json for 2 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/fd0d9515e6af
Author: James Lal <james@lightsofapollo.com>
Desc: Merge pull request #11539 from lightsofapollo/bug-901850-product

Bug 901850 - marionette-js-runner symlink app contents

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https://hg.mozilla.org/integration/gaia-central/rev/270d0eb11c7b
Author: James Lal <james@lightsofapollo.com>
Desc: Bug 901850 - marionette-js-runner symlink app contents

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "72615b79efd626f6bf2f338cf888b6383b1dda0f", 
+    "revision": "fd0d9515e6af1d7fdf8d40133d4706eb6e4b5938", 
     "repo_path": "/integration/gaia-central"
 }